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and granitic rocks. Conversely, the intermediate unit is made up almost exclusively of mafic rocks and much scarcer ultramafic varieties, and only two metagranitic bodies of metric dimensions. This intermediate unit has been interpreted as an ophiolite, the Mérida Ophiolite (Díez Fernández et al . 2022), in which the gabbroic pro- toliths have been dated at 596 Ma (U-Pb in zircon), the protoliths of the few intrusive granites in the ophiolite at Figure 13. Plots showing the chemical characteristics of garnet, plagioclase and amphibole in the garnet amphibolites (sample 117,350). a), b) Compositional profiles in garnets. c) Garnets compositions projected in the diagram of Coleman et al . (1965). A, B, C represent compositional domains for garnets of their respective eclogite types. The diagram is used to show comparison with eclogitic garnets. d) Composition of plagioclases in the Kfs-Ab-An diagram. e) Classification of amphiboles (Hawthorne et al . 2012). INTERNATIONAL GEOLOGY REVIEW 21 Mérida Ophiolite (SW Iberia)